It is not unusual for patients prior to their total hip arthroplasty (THA) to indicate that their symptoms worsen with certain meteorological conditions. However, the prevalence and evolution of weather-related pain (WRP) following THA remain poorly understood. The aim of this study was to investigate the prevalence of WRP both before and after primary THA, to assess the impact of THA on pre-existing WRP, and to identify potential risk factors associated with WRP. An in-person survey was conducted on 442 primary THAs, in 327 consecutive patients at the time of their postoperative follow-up. Each patient was assessed using a questionnaire specifically designed to address weather-related joint pain before and after their THA. The clinical evaluation included patient-reported outcome scores (PROMS). Preoperatively, 17% of THA hips experienced WRP, with 71% achieving complete resolution postoperatively (p < 0.001). In patients with WRP in multiple joints and their hip, the THA failed to alleviate the WRP in 31% of the cases. In addition, 8% of the THA patients developed de-novo WRP after surgery. Although the overall prevalence of WRP in hips post-THA was 12%, the prevalence was 29% in hips with WRP preoperatively and 31% in the hips of patients with WRP in multiple joints as well as their hip. WRP in other joints, the initial diagnosis, body mass index (BMI), and age were correlated with WRP following THA. WRP is not uncommon prior to and after THA. Although THA can effectively alleviate WRP in specific patient populations, it does not universally eliminate preoperative WRP or prevent the emergence of new WRP after surgery.
The purpose of this study was to evaluate the biological fixation of a 3D printed porous implant, with and without different hydroxyapatite (HA) coatings, in a canine model. A canine transcortical model was used to evaluate the characteristics of bone ingrowth of Ti6Al4V cylindrical implants fabricated using laser rapid manufacturing (LRM). At four and 12 weeks post-implantation, we performed histological analysis and mechanical push-out testing on three groups of implants: a HA-free control (LRM), LRM with precipitated HA (LRM-PA), and LRM with plasma-sprayed HA (LRM-PSHA).Aims
Materials and Methods
Porous surfaces developed over the past decades have been shown to promote tissue ingrowth. Hydroxyapatite (HA) coatings have been added to these porous coatings in an attempt to further augment bone ingrowth. The development of additive manufacturing techniques has allowed for precision in building these complex porous structures. The effect of supplemental HA coatings on these new surfaces is unclear. The purpose of this study is to evaluate the biological fixation of a novel 3D printed porous implant in a canine model. In addition, we evaluated the effect of different HA coatings on this 3D printed implant. A canine transcortical model was used to evaluate the performance of three different laser rapid manufacturing (LRM) Ti6Al4V cylindrical implants (5.2 mm diameter, 10mm length): LRM with precipitated hydroxyapatite (P-HA), LRM with plasma sprayed hydroxyapatite (PS-HA), and a hydroxyapatite-free control (No-HA). The implants were 50–60% porous with a mean pore size of 450 μm and have a random interconnected architecture with irregular pore sizes and shapes that are designed based on the structure of cancellous bone. A lateral approach to the femoral diaphysis was used to prepare 5 mm unicortical, perpendicular drill holes in 12 canines. One of each implant type was press-fit into each femur. The femora were harvested at both 4 and 12 weeks post implantation, radiographed and prepared for either mechanical push-out testing to assess the shear strength of the bone-implant interface (left femora, N=6) or for histological processing (right femora, N=6). An un-paired Student's t-test was used to compare statistical significance between the 4 and 12-week results, as well as differences due to implant type; p<0.05 was considered significant.Introduction
Methods
Dislocation is one of the most common complications after revision THA using the posterolateral approach. Although the cause of dislocation after revision THA is multifactorial, the historically high dislocation rates have been shown to be significantly reduced by closing the posterior capsule and by the use of large diameter (36 and 40 mm) femoral heads. The relative importance of each of these strategies on the rate of dislocation remains unknown. We undertook a study to determine if increasing femoral head diameter, in addition to posterior capsule closure would influence the dislocation rate following revision THA. We retrospectively reviewed 144 patients who underwent a revision THA. We included all patients who underwent revision THA with closure of the posterior capsule and who had at least a 2-year minimum follow-up. We excluded patients undergoing a revision THA for dislocation or multistage revision for infection since these patients would likely have deficient posterior tissues. Forty-eight patients had a 28 mm femoral head, 47 had a 32 mm head and 49 patients had a 36 mm femoral head. At a minimum follow-up of 2 years, there were 3 dislocations. There were no dislocations in the 28 mm group (0%), 2 in the 32 mm group (4%) and 1 in the 36 mm group (2%). All patients were successfully treated with a closed reduction. No patients had recurrent dislocation. Head size alone was not found to significantly decrease the risk of dislocation (28mm vs 32mm p=0.12; 28mm vs 36mm p=0.27; 32mm vs 36mm p=0.40). Both large diameter heads and careful attention to surgical technique with posterior capsule closure can decrease the historically high dislocation rate after revision THA when utilizing the posterolateral approach. The additional use of a large diameter head did not have a significant impact on the already low dislocation rate. Capsular closure outweighs the effect of femoral head diameter in preventing dislocation following revision THA through a posterolateral approach.
